Alginate acted as a support to protect and to reinforce the core materials.
Incorporation with graphene oxide prevented the leaching of Fe3O4 nanoparticles.
Synergistic effects of adsorption and ion exchange facilitated the distinct uptake.
Release of Fe3+ from iron crosslinked mGO/beads enhanced the removal of Cr(VI).
mGO/beads performed for at least 5 cycles without leaching of core materials.